electric cooling fan revisited. (1 Viewer)

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John

i got the idea from the dodge cummins forum where it is generally considered an upgrade for summer towing and off road conditions.

i can see some disadvantages.
electrical failure
to demanding for the alternator

there must be more that i'm missing, please elaborate.

thanks
 
WHATS TO CONSIDER, JUST DO IT! DONT BE FOOLED,
COOLING IS COOLING. AS LONG AS YOUR RIG IS NOT OVER HEATING ITS ALL GOOD. i TOOK MY CLUTCH FAN OUT & PUT IN ELECTRIC WITH 3 POSITION SWITCH. ON/OFF/AUTO. I CAN TURN OFF NOW WHEN CROSSING DEEP WATER & TURN ON WHEN SITTING IDLE IN 3O DEGREE HEAT. :bang:
 
I use both, electric as auxiliary, or redundancy. Have electric water pump too, alsoaux/redundancy.
 
I removed my fan and replaced it with an electric one, zero overheating problems and a noticeable increase in power without the drag of the fan.
 
Gold Boy said:
John

i got the idea from the dodge cummins forum where it is generally considered an upgrade for summer towing and off road conditions.

i can see some disadvantages.
electrical failure
to demanding for the alternator

there must be more that i'm missing, please elaborate.

thanks
Click to expand...

I cant see the reason for doing the mod. All my cruisers OEM cooling systems work fine in 40c heat.
With the cold weather you guys endure,the more cranking power left in the battery ,the better
 
- Electrics do not offer more air movement than an engine-driven fan, in virtually all applications it is far, far less
- Most of the air movement over the rad at highway speeds is due to the movement of the vehicle and not the fan
- Clutched fans that are working properly do not rob extra power, they freewheel most of the time
- Clutched fans do not create problems during water crossings since they disengage - there is much more to the water crossing thing, but most fans are not a problem in deeper water. Note that many people don't even venture into water that deep in any case.
- Engine-driven is more reliable
- At low speeds, most diesels produce little heat and do not need the mythical "extra" cooling

~John
 
Your point about clutched fans not robbing power is a bit of a half truth, anytime the clutch is engaged it is robbing power
 
BEE-JAY42 said:
Your point about clutched fans not robbing power is a bit of a half truth, anytime the clutch is engaged it is robbing power
Click to expand...

Oh, boy.... do I have to include caveats with every explanation ?

The issue is "robbing" power - which they are not technically doing when they are performing their job. An electric, in that case, is actually adding a greater degree of inefficiency when doing its job than an engine-driven clutch fan.

I think it's pretty obvious that when the fan is being driven and the clutch is engaged, that the fan is using up some power from the engine. The fact remains that they provide far more cooling power than an electric, and that most of the time they are freewheeling.

~John
 
good point on the fact that diesels do idle relatively cool.

there is no doubt that viscous clutch fans do work very well and that is why toyota have them on there cruisers.

a situation where an electric fan could be superior, is 40C climbing "off road" a long steep hill, your rpm's are low so the clutch fan is not turning that fast for effective air flow, in this situation i would think an electric fan would make for a more efficient cooling.

i believe that my cooling system is working correctly, yet in the middle of summer when it's hot it is not to hard to get 13bt hotter than i am comfortable with.

out of curiosity, on the new diesel land cruisers do they use electric fans?


.0000000002 cents LOL.... :D
 
Gold Boy said:
a situation where an electric fan could be superior, is 40C climbing "off road" a long steep hill, your rpm's are low so the clutch fan is not turning that fast for effective air flow, in this situation i would think an electric fan would make for a more efficient cooling.
Click to expand...

I tested mine in low range,in thick soft sand in 2nd gear low range with 40 psi inthe tyres. The heat radiating off the sand is an added load.The engine got to 94c and then dropped off to mid 80s



out of curiosity, on the new diesel land cruisers do they use electric fans?


.0000000002 cents LOL.... :D
Click to expand...
The pics I have look like it has a viscous fan but Im not 100% on that.

I read once that the reason car manufacturers went to electric fans was that overall the electric fan is lighter than the viscous fan clutch.
With the small frontal section of modern cars the electric fan can be positioned where it fits or they can use 2 small fans.
Where as the viscous fan must be in alignment with the other pulleys.
There is a of rule that says the fan must cover 70% of the radiator surface to be effective and the electric fans can be more space efficient.
 
how much amps the electric fan need to proper operations . ?

how much CFM muve the factory fan . ?

IMOP nice to have an auxiliary electric fan .. but one that move more than 2200 CFM will draw good amps from our poor alternators ..
 
Radd you've got over 4,000 posts surely you've learnt by that no matter how much detail you include there will always be someone who picks you up on some irrelevant detail ;). Anyway just wanted to make sure that no one misinterpreted your post.

I have a BJ42 with a 3B that had a direct drive fan (no clutch that is) and it uses a noticable hunk of power, i'm a person who is very sceptical when people say they made some improvment and felt the extra power (I feel most the time the only real gain is psychological), but you can genuinely notice the difference, probably due to the low power figure you start with in a 3B. No overheating at all, the only time you even need the fan is on long large hills and when your off road. If you have an engine with a direct drive fan and are chasing a couple of extra horses i'd highly recommend it.
 
I'm about to shell out $200 bucks to replace my fan clutch
so I certainly looked at an electric as an alternative but the following argument made a lot of sense to me:

The mechanical fan is driven by the motor with very little wasted power (friction from the belt?)
The electric fan is driven from the alternator, via wires that do drop voltage/heat, then the electric motor is less than 100% efficient, and the alt is less than 100% efficient, and the belt friction is the same (or more) for the alt as the fan.

With that in mind..... How do you figure that the electric fan is more efficient? Ever?

Sure... a broken viscous coupler will spin when the motor is cool, thus wasting power. But if all works correctly, it seems impossible that the electric is more efficient.

As for low speed: if the fan locks up and is moving at about 1,000rpm, then it is probably cooling pretty well. An aux electric fan might help.
 
I just don't see how it is possible for the electric fan to sue less engine power.....

in simple efficiency terms, how can you get more movement out of something that converts engine movement to electricity, then converts it back to motor movement.... than you do out of something that just spins with the engine?

I guess that maybe having the battery involved might mean that the load on the motor is spread out over more time?

regardless: I've got the stock electric pusher fan as well as the viscous coupler and think that is a great system. When the AC compressor is on, the pusher kicks in. I'd like to add a temp probe so that whenever the radiator hits a given temp, the pusher kicks in... as that would be even better for cooling, I think. But for now, I'm happy with what I've got.
 
Actually Steve that's the key .. the electric fan draw certain amount of amps from the alternator .. and this one need to " work " harder to produce 'em ( little more complicated than that )

with more effort from the alt .. if place more draw from the engine .. quite simple.

The question is .. how much it takes from the alt and how much the alt take from the engine, and compare it to the needs from a traditional fan.
 
1- Electric fan is ineffecient
2- Alternator is ineffecient
3- Belt fan is ineffecient

(everything is ineffecient)

You want to combine two ineffecient processes, and get more power, than just using one ineffecient process.



I would be interested in an electric fan on an intercooler, or inside my cruiser, but that is it.
 
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